Branch assembly for a communication bus

Abstract

A branch assembly for a communication bus is shown that allows easy connection and removal of devices from the bus. A switch is located within each assembly to direct the bus either from one bus interface directly to a second bus interface or from one bus interface through a branch interface to the second bus interface, as appropriate depending on the presence of device at the branch interface. The switch is integrated into the assembly and is mechanically actuated by the presence or absence of a connector at the branch interface.

I claim:  
     
       1. A branch assembly for an electrical bus, comprising: 
       a housing,  
       a first and a second bus interface disposed on a periphery of said housing;  
       a branch interface disposed on the periphery of said housing;  
       a switch disposed within said housing, said switch having an open and a closed state;  
       a first set of at least one electrical conductors extending from said first bus interface to said switch and a second set of electrical conductors equal in number to said first set, said second set extending from said second bus interface to said switch;  
       a third set of electrical conductors equal in number to said first set, said third set of electrical conductors extending between said first set of electrical conductors and said branch interface, said third set of electrical conductors in electrical communication with said first set of electrical conductors;  
       a fourth set of electrical conductors equal in number to said second set, said fourth set of electrical conductors extending between said second set of electrical conductors and said branch interface, said fourth set of electrical conductors in electrical communication with said second set of electrical conductors;  
       an actuator located on said switch placing said switch in the closed state when said branch interface is unoccupied and placing said switch in the open state when said branch interface is occupied; and  
       wherein said switch places said first set of electrical conductors in electrical communication with the corresponding electrical conductors of said second set when said switch is in the closed state, and prevents any electrical communication between the first and second set of electrical conductors when said switch is in the open state.  
     
     
       2. The assembly of  claim 1 , further comprising a circuit board mounted within said housing, whereupon said switch is located. 
     
     
       3. The assembly of  claim 2 , wherein the connections between said first and third sets of electrical conductors and the connections between said second and fourth sets of electrical conductors are located on said circuit board. 
     
     
       4. The assembly of  claim 3 , wherein said bus interfaces and said branch interface are of like shape and size. 
     
     
       5. The assembly of  claim 4 , wherein said bus interfaces have means to receive female connectors, and said branch interface has means to receive a male connector. 
     
     
       6. The assembly of  claim 3 , further comprising an opening in said branch interface, said opening aligned with said switch actuator. 
     
     
       7. The assembly of  claim 6 , wherein said actuator is operated by a protrusion from a connector on the branch interface. 
     
     
       8. The assembly of  claim 3 , wherein said bus interface and said branch interface are of necessary shape and size to be used with an RS-485 communication bus. 
     
     
       9. A communication bus comprising: 
       a plurality of branch assemblies placed in a logical sequence, each of said branch assemblies comprises:  
       a housing;  
       a first and a second bus interface disposed on a periphery of said housing;  
       a branch interface disposed on the periphery of said housing;  
       a switch disposed within said housing, said switch having an open and a closed state;  
       a first set of at least one electrical conductors extending from said first bus interface to said switch and a second set of electrical conductors equal in number to said first set, said second set extending from said second bus interface to said switch;  
       a third set of electrical conductors equal in number to said first set, said third set of electrical conductors extending between said first set of electrical conductors and said branch interface, said third set of electrical conductors in electrical communication with said first set of electrical conductors;  
       a fourth set of electrical conductors equal in number to said second set, said fourth set of electrical conductors extending between said second set of electrical conductors and said branch interface, said fourth set of electrical conductors in electrical communication with said second set of electrical conductors;  
       an actuator located on said switch placing said switch in the closed state when said branch interface is unoccupied and placing said switch in the open state when said branch interface is occupied; and  
       wherein said switch places said first set of electrical conductors in electrical communication with said second set of electrical conductors when said switch is in the closed state, and prevents any electrical communication between the first and second set of electrical conductors when said switch is in the open state; and  
       at least one cable, each cable placing said first bus interface of one assembly in electrical communication with a bus interface of an adjacent assembly.  
     
     
       10. The communication bus of  claim 9 , further comprising an electrical termination on said second bus interface of the first logically sequenced assembly and an electrical termination on said first bus interface of the last logically sequenced assembly. 
     
     
       11. The communication bus of  claim 9 , further comprising connection means for placing a communicating device in electrical communication with one of said branch interfaces. 
     
     
       12. The communication bus of  claim 11 , further comprising a protruding tip on the end of each said connector. 
     
     
       13. The communication bus of  claim 12 , further comprising an opening in at least one of said branch interfaces, said opening aligned with said actuator.